Plant extract-mediated synthesis of aluminum oxide nanoparticles for water treatment and biomedical applications: a review.

Nanotechnologies have contributed to disease control and prevention, but conventional synthesis of nanoparticles rarely meets the strict requirements of green chemistry. Alternatively, plant extract-mediated synthesis of nanoparticles avoids the use of toxic chemicals, and requires low amounts of energy. Herein, we review plant extract-mediated synthesis and applications of Al2O3 nanoparticles in water treatment and biomedical use. As substitutes for less eco-friendly chemicals, phytochemical compounds such as polyphenols, quercetins, flavonoids, and alkaloids found in plant extracts play a crucial role as capping and complexing agents for the synthesis of Al2O3 nanoparticles. They exhibit emerging characteristics of high specific surface area of 54.5–228.7 m2/g, small particle size of 2–100 nm, diverse shape and crystal phase. Green Al2O3 nanoparticles and Al2O3-based nanocomposites could efficiently remove 93–98% contaminants such as organic dyes, fluoride and nitrate from water. Antibacterial, antifungal, and antioxidant activities of green Al2O3 nanoparticles are presented. In addition, we discuss some of the shortcomings of green aluminum oxide nanoparticles as well as the recent developments in their use in environmental mitigation and biomedical applications. [ABSTRACT FROM AUTHOR]